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Lexington Avenue #6 subway trains stop at the East 23rd Street station on Park Avenue South. Express #4 and #5 subways stop at Union Square. N and R subway trains stop at the East 23rd Street station on Broadway; frequent service is provided 24 hours a day, seven days a week. Frequent bus service is provided by routes M-6 and M-7 on Broadway, by route M-1 on Park Avenue South and by route M-23 operating cross town on 23rd Street; service is provided 24 hours a day, seven days a week.